Re: [2.6.0-test9] QoS HTB crash...

David S. Miller
2003-10-30T21:16:15Z

On Thu, 30 Oct 2003 20:50:16 +0100 (CET)
devik <devik@cdi.cz> wrote:

> thanks for the report. I know that there is an issue regarding
> HTB in 2.6.x. Please send me net/sched/sch_htb.o,
> net/sched/sch_htb.c (just to be sure) and be sure that you
> build the kernel with debugging symbols (see debugging section
> of menuconfig/xconfig).

I think the problem is the changes that were made
in 2.5.x to htb_next_rb_node(). It used to be:

static void htb_next_rb_node(rb_node_t **n)
{
rb_node_t *p;
if ((*n)->rb_right) {
/* child at right. use it or its leftmost ancestor */
*n = (*n)->rb_right;
while ((*n)->rb_left)
*n = (*n)->rb_left;
return;
}
while ((p = (*n)->rb_parent) != NULL) {
/* if we've arrived from left child then we have next node */
if (p->rb_left == *n) break;
*n = p;
}
*n = p;
}

But it was changed into:

static void htb_next_rb_node(struct rb_node **n)
{
*n = rb_next(*n);
}

This is wrong, the new code has much different side effects
than the original code.

This looks like the problem, devik what do you think?